Power-syringe.



Patented June 27, 1911.

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J. PAYNE & J. E. KNAPP.

POWER SYRINGE- APPLIOATIQN FILED JULY 18,1910.

PL411$ -JJ rus NORRIS PETERS ca, WASHINGTON, n. c

JOSEPH PAYNE AND JOHN E. KNAPP, 0F BELMONT, MASSACHUSETTS; SAID KNAPP ASSIGNOR TO SAID PAYNE.

POWER-SYRINGE.

Specification of Letters Patent.

Application filed July 18, 1910.

Patented June 27, 1911.

Serial No. 572,415.

T 0 all whom it may concern:

Be it known that we, J OSEPH PAYNE and JOHN E. KNAPP, both of Belmont, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Power-Syringes, of which the following is a specification.

This invention which relates chiefly to a hypodermic dental syringe, the barrel of which is controlled by the hand of the operator while the delivering end of the syn inge is in the patients mouth, has for its object to enable the plunger which ejects liquid from the syringe to be manipulated by power transmitted through the flexible shaft of a dental lathe, so that no muscular eflort is required by the operator in moving the plunger, the operator being enabled to more accurately control and guide the syringe than would be the case if he were obliged, while controlling and guiding the syringe, to also project the plunger.

To this and other related ends, the invention consists in the improvements which we will now proceed to describe and claim.

Of the accompanying drawings which form a part of this specification,Figure 1 represents a side elevation on an enlarged scale of a power dental syringe embodying our invention. Fig. 2 represents a section on line 22 of Fig. 1'. Fig. 3 represents a section on line 33 of Fig. 2. Fig. 4 repsleeve, hereinafter referred to. Fig. 5 represents a section on line 55 of Fig. 2.

In the drawings, 12 represents the liquidcontaining portion of the barrel of the dental syringe, which is provided at its outer end with the usual or any suitable means for connecting a hypodermic needle with the barrel, said means as here shown comprising a screwthreaded nipple 13 formed on the outer end of the barrel.

1 1 represents the plunger, which has a close sliding fit within the barrel portion 12 and is adapted to eject liquid therefrom.

The barrel portion 12 is provided with an extension 12 which in turn is provided with an extension 12 the latter constituting a case for the plunger-operating mechanism hereinafter described. The barrel portion 12 and the extensions 12 and 12 constitute a sectional barrel, the said parts being suitably connected as by the screw-thread connections represented at 15 and 16, Fig. 2.

ably of hardened steel.

The extension 12 has a considerably greater internal diameter than the external diameter of the plunger for the greater portion of its length, sald extension being provided with a contracted portion 17 which closely fits and guides the plunger and confines an annular packing 18 interposed between said contracted portion and the inner end of the barrel portion 12, provlsion being thus made for preventing leakage of fluid in to the extension 12*.

19 represents a screw-threaded plungeroperating shaft which is journaled to rotate without moving endwise in the extension 12, an antifrict-ional bearing being prefertional balls 23 engaged with said races. The

'plate 21 is clamped at its margin between the extensions 12 and 12 and the plate 20 is seated on a contracted portion 2 1 of the extension 12, said contracted portion being formed to surround the upper portion of the shaft 19 without having a frictional bearing thereon. The plates 20, 21, are prefer- The inner end portion of the plunger 14: is internally threaded at 25 and constitutes a nut which engages the screw thread of the shaft 19. resents a perspective view of the clutch 26 represents a shaft member which is journaled in a bearing 27 formed in the extension or casing 12 and projects from said casing, the journaled shaft member 26 being adapted at its outer end for engagement avith a flexible shaft member such as that employed in a dental lathe.

28 represents a primary driving gear fixed to the inner end of the driving shaft member 26, and located within the casing 12.

29 represents a secondary driving gear which is mounted to rotate loosely on the plunger-operating shaft 19. The gears 28 and 29. are preferably bevel gears.

The primary gear 28 is provided in its under side with a downwardly projecting clutch tooth or member 30, and the secondary gear 29 is provided on its upper side with an upwardly projecting clutch tooth or member 81. The plunger-operating shaft 19 is provided with a squared extension 19 which extends across the space between the gears 28 and 29 and terminates in a cylindrical end portion 32 which is adapted to rotatev are journaled in bearings formed for their 7.

reception in the inner surface of the casing 12*, said intermediate gears meshing simultaneously with the gears 28 and 29 and imparting motion from the former to the latter, the secondary gear 29 being rotated in a direction opposite that of the rotation of the primary gear 28.

represents a clutch sleeve which is provided with a squared longitudinal passage 36 (Fig. 4) closely fitting and adapted to slide endwise on the squared portion 19 of the plungeroperating shaft. The clutch sleeve is provided at its ends with clutch members 37 and 38 which face in opposite directions and are adapted to respectively engage the gear clutch members 30 and 31. The clutch sleeve is shorter than the space between the gears 28 and 29, its length being such that its clutch members 37 and 38 are adapted to engage the gear clutch members 30 and 31 alternately but not simultaneously.

39 represents a shifting rod which is provided with an arm 40 projecting into an annular groove 410 in the periphery of the clutch sleeve. The shifting rod is movable endwise in the guides 41 and 42, the guide 41 being the wall of an orifice formed in the inner end of the casing 12", while the guide 42 is a perforated ear fixed to the extension 12 the main portion of the shift ing rod being outside the casing 12 and extending along one side of the extension 12 The lower end of the shifting rod is bent to form a handle 43 for the convenience of the operator in moving the rod.

It will be seen from the foregoing that when the clutch sleeve 35 is moved outwardly toward the primary gear 28, its clutch member 37 engages the clutch member 30 of said gear, the clutch member 38 being at the same time disengaged from the clutch member 31 of the secondary driving gear. The plunger-operating shaft is therefore rotated by the primary gear 28 alone, but in the same direction as said gear. WVhen the clutch sleeve is moved downwardly its clutch member 38 is engaged with the clutch member 31 of the secondary driving gear, and its clutch member 37 is at the same time disengaged from the clutch member 30 of the primary gear, the rotation of the plunger-operating shaft being now caused by the secondary driving gear 29, the shaft being therefore rotated in a direction opposite that first described. It will now be seen that the operator is enabled by adjusting the clutch sleeve 35 to cause the shaft 19 to rotate in either direction andeither project or retract the plunger. The clutch sleeve is preferably of such length that it is adaptedto occupy an inoperative intermediate position out of engagement with the clutch members of each ofthe driving gears.

The shifting rod 39 is preferably provided with a series of indicating marks or notches 45, three in number, which are arranged so that their positions relatively to the guide 42 indicate the position of the clutch sleeve,that is to say, when the upper mark 45 coincides with the upper side of the guide 42, the clutch sleeve is engaged with the secondary gear 29, as shown by Fig. 2, and when the lower mark 45 coincides with the guide 42 the clutch sleeve is engaged with the primary gear 28, the coincidence of the intermediate notch with the upper side of the guide, indicating that the clutch sleeve is in its intermediate inoperative position.

Means are provided for automatically moving the shifting rod by the movement of the plunger, said means comprising an arm 46 attached to the plunger and projecting through a longitudinal slot 47 in the extension l2 said arm being formed to surround the shifting rod, and two tappets 48 and 49, adjustably secured by set screws 50 to the shifting rod, one above and one below the arm 46.

hen the arm 46 strikes thetappet 49 during the downward movement of the plunger, it partially moves the rod 39 in the direction required to cause the retraction of the plunger, this movement of the rod being completed by the operator after the clutch members are thrown out of engagement.- Then the arm 46 strikes the tappet 48 during the. retraction of the plunger, it partially moves the shifting rod in the direction required to again reverse the movement of the plunger, the movement of the rod being again completed by the operator.

The arm 46 may be provided with a pointer 57 (Fig; 1) which cooperates with the graduated scale 52 formed on or attached to the extension 12 Said scale enables the tappets 48 and 49 to be adjusted so that each downward movement of the plunger will discharge a predetermined quantity of liquid and the retracting movement of the plunger will cause it to draw a predetermined quantity of liquid into the barrel portion 12.

An apparatus embodying the essential features of the invention may be used for forcing a lubricant such as grease into a hearing. In other words, the device substantially as herein shown and described may be used as a grease gun to lubricate bearingsof motor vehicles, the above-mentioned flexible shaft being connected in any suitable way with the motor of the vehicle.

Our invention when embodied in a hypodermic dental syringe, enables the operator to quickly and delicately manipulate the needle of the instrument in the mouth of the patient without any unsteady motion or jar tending to injure or pain the patient;

This described result is due to the fact that the power which projects the plunger is transmitted from an external source, so that no pressure against the instrument is required tending to displace or jar the needle, such as would be exerted by hand operation of the plunger-projecting means, the syringe being held by one hand of the operator and the plunger-impelling means operated by the other hand.

WVe claim:

1. A power syringe comprising a barrel, a plunger movable therein, a screw-threaded operating shaft journaled in the barrel and engaged with the plunger, and power-driven mechanism carried bythe barrel for rotating said shaft, said mechanism including a journaled driving shaft member adapted to engage a flexible driving shaft member.

2. A power syringe comprising a barrel, a plunger movable therein, a screw-threaded operating shaft j ournaled in the barrel and engaged with the plunger, power-driven mechanism carried by the barrel for rotating said shaft, said mechanism including a journaled driving shaft member adapted to engage a flexible driving shaft member, and means for adjusting said mechanism to rotate the plunger-operating shaft in either direction.

8. A power syringe comprising a barrel, a plunger movable therein, a screw-threaded operating shaft journaled in the barrel and engaged with the plunger, a casing attached to the barrel and constituting an extension thereof, and powerdriven mechanism mounted in said casing for rotating the shaft, said mechanism including a power-transmitting shaft member journaled in and projecting from the casing, and adapted to engage a flexible driving shaft member.

4. A power syringe comprising a barrel, a plunger movable therein, a screw-threaded operating shaft journaled in the barrel and engaged with the plunger, a casing attached to the barrel and constituting an extension thereof, a driving shaft member journaled in and projecting from the casing, and adapted to engage a flexible driving shaft member and mechanism carried by the casing for imparting rotary movement from the said journaled shaft member to the plunger-operating shaft.

5. A power syringe comprising a barrel,

a plunger movable therein, and mechanism supported by the barrel for impelling the plunger, said mechanism including a journaled driving shaft member provided with means for engaging a flexible power-transmit-ting shaft, and intermediate connections between the said member and the plunger whereby the plunger may be projected by power transmitted from an external source without effort on the part of the operator tending to shake or jar the instrument.

In testimony whereof we have affixed our signatures in presence of two witnesses.

JOSEPH PAYNE. JOHN E. KNAPP. Witnesses:

C. F. BROWN, P. W. Pnzzn'r'rr.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

